Control device indicator



Dec. 21, "1948. D. B. KEIM 2,456,949

:CONTROL 'DEVICE 'INDICATOR Filed sept. so, 1947 lzrwvert @1^ z 'DonaldB. Keim,

5M "His Attorney Patented Dec.. 21, 1948 CONTRL DEVICE INDECATOR YorkApplication September 30, i947, Serial No. 776,884

2 Claims. i

My invention relates to control device indicators, and moreparticularly, to an indicator for a channel selector switch, bandswitch, or similar control device of the type commonly used on radio andtelevision receivers and the like. It is a primary object of myinvention to provide an improved arrangement of this type whichfacilitates proper adjustment of the control device.

In the case of a channel selector switch on a television receiver, forexample, it is customary to employ a rotary type switch, the operatingshaft of which is enclosed concentrically in a tubular shaft whichactuates the oscillator trimmer. Such an arrangement requires the use ofdual coaxial knobs in order to allow independent Operation of the twocontrols. The inner knob is customarilyattached to the tubular shaft, oroscillator trimmer control, while the outer knob is conventionallyattached to the inner shaft, or channel selector switch control.

It is a particular object of my invention to provide a compact,economical indicating device, to be used in conjunction with the outerknob, which facilitates rapid selection of the desired frequency channelof operation.

The features of my invention which 1 believe to be novel are set forthwith particularity in the appended claims. My invention itself, however,together with further objects and advantages thereof, may best beunderstood byrreference to the followingl description taken inconnection with the accompanying drawing, in which Fig. 1 is a view intransverse section of a dual knob arrangement suitably embodying myinvention; Fig. 2 is a front View of the assembly of Fig. l; Fig. 3 is across-sectional View of another embodiment of my invention; and Fig. 4is a front view of the assembly of Fig. 3. Like reference numeralssignify similar elements in the several figures.

In the accompanying drawing, referring to Figs. l and 2, have shown myinvention cornprising an inner control knob l and an outer control knob2, mounted coaxially and independently on two concentric operatingshafts 3, l in a manner well known in the art. Control knob i is of theconventional round type, and is attached to the outer, tubular shaft 3,which may, for example, control the oscillator trimmer of a televisionreceiver. The inner knob l is composed of wood, plastic, or othersuitable insulating material and is substantially circular in shape. Theouter periphery of control knob l may be ridged or knurled for ease ofoperation. An axial hole 5 is provided with means for attaching the knobl to the tubular shaft 3, such means as shown (Cl. 11G-i242) 2 takingthe form of a pair of oppositely disposed keys 6 on the inside of theaxial hole 5 and corresponding keyways in the tubular shaft 3. Thetubular shaft 3 is slightly spread to provide rm frictional engagement.The inner knob l may be provided with a centrally located indentation orsocket portion l, the purpose of which is to provide ready access of theouter knob 2 to the solid shaft li, and to provide compactness ofassembly.

Control knob 2 is of the bartyDe with certain adaptations, and isattached to the inner, solid shaft l, which may control the channelselector switch. The outer knob 2 is composed of suitable ornamentalmaterial, and is provided with a substantially bar-shaped rectangularhead portion 8 and a protruding base portion 9 which extends axiallyinto the recess l of control knob l. I also provide control knob 2 withan extension or dependingl portion lil extending substantially parallelwith the shafts 3, 6l, and of such dimensions as to permit the assemblyof an indicating dial il so that the latter will clear both the frontpanel l2 of the cabinet and the inner knob i. The outer knob-and-dialassembly is tted to the inner shaft i by means similar to those employedfor fitting the inner knob i to the tubular shaft (i. The front panel l2of the cabinet is provided with a pilot light i3, or some similarsuitable reference device.

A circular metal indicating dial li is provided, suitably engraved withindicia M so that, for each position of the channel selector switch, adistinguishing marking is brought into alignment with the pilot lighti3. The indicating dial il is assembled to the outer knob 2 by a screwl5, or other similar device, which extends through a clearance hole itin the indicating dial il into a threaded hole il in the extension lllof control knob 2. Thus, the dial ll completely surrounds the inner knobi without touching it, and there is a small clearance between theindicating dial ll and the front panel l2 of the cabinet. In thismanner, the indicating dial il is caused to rotate as an integral partof the outer knob 2, and the operating channel is indicated by themarking l@ on the indicating dial i l which is in alignment with thepilot light i3.

Figs. 3 and 4 show a similar assembly wherein the inner knob l isassumed to operate a band switch. The outer knob 2 is provided with anindicating dial ii, as before. However, in this application, the innerknob l is also provided with an indicating dial I8 comprising suitableindicia i9 to identify the position of the band switch when in alignmentwith the pilot light I3. Hence, both switches may be rapidb' adjusted bybringing the proper markings into alignment with the pilot light.

While I have shown and described particular apparatus which embodies myinvention, it will be understood that this is for the purpose ofillustration of principles involved, and that many modifications may bemade Without departing from the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A control knob arrangement for a pair of coaxial shafts comprising afirst knob adapted to engage the outer of said shafts, said first knobhaving a hole extending longitudinally thereof, the inner of said shaftsextending through said hole, a second knob being attached to said innershaft, said second knob having a depending portion extendingsubstantially parallel with said second shaft and spaced from saidsecond shaft by a distance greater than the radius of said iirst knob,and an annular dial attached to said depending portion, said dial havinga central aperture having a diameter greater than the diameter of saidfirst knob, and said dial having indicia thereon for indicating theposition of said second knob.

2. A control knob arrangement for a pair of coaxial shafts, the outer ofsaid shafts having mounted therein a circular knob having a longisaidshafts projecting into said socket portion,

a second knob having a rectangular head portion and a rounded baseportion adapted to extend into said socket portion, said second knobhaving a longitudinally extending arm connected to one end of said headportion, said second knob having a longitudinally extending recessadapted to engage the inner of said shafts, said longitudinallyextending arm being displaced from said recess by a distance greaterthan the radius of said rst knob, an annular disk attached to saidlongitudinally extending arm at its end remote from said rectangularhead portion, said disk having an aperture of diameter greater than thediameter of said flrst knob and arranged to encircle said rst knob, saiddisk having indicia marked thereon, and means displaced from said shaftsfor indicating the position to which said inner shaft is adjusted, saidlast meansv comprising a panel having an aperture through which saidshafts project and indicia marked on said panel.

DONALD B. KEIM.

No references cited.y

